Journal
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Volume 39, Issue 3, Pages 1564-1570Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijhydene.2013.04.112
Keywords
Direct methanol fuel cell; Diffusion media; Methanol crossover; High concentration methanol fuel
Categories
Ask authors/readers for more resources
Reducing methanol crossover from the anode to cathode in direct methanol fuel cells (DMFCs) is critical for attaining high cell performance and fuel utilization, particularly when highly concentrated methanol fuel is fed into DMFCs. In this study, we present a novel design of anode diffusion media (DM) wherein spatial variation of hydrophobicity along the through-plane direction is realized by special polytetrafluoroethylene (PTFE) coating procedure. According to the capillary transport theory for porous media, the anode DM design can significantly affect both methanol and water transport processes in DMFCs. To examine its influence, three different membrane-electrode assemblies are fabricated and tested for various methanol feed concentrations. Polarization curves show that cell performance at high methanol feed concentration conditions is greatly improved with the anode DM design with increasing hydrophobicity toward the anode catalyst layer. In addition, we investigate the influence of the wettability of the anode microporous layer (MPL) on cell performance and show that for DMFC operation at high methanol feed concentration, the hydrophilic anode MPL fabricated with an ionomer binder is more beneficial than conventional hydrophobic MPLs fabricated with PTFE. This paper highlights that controlling wetting characteristics of the anode DM and MPL is of paramount importance for mitigating methanol crossover in DMFCs. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available